Fluid　solidified　soil　is　a　new　material　developed　in　recent　years　to　improve　backfill　quality　of　narrow　space　in　municipal　and　construction　engineering.　In　this　paper,　steel　slag　powder,　CFB　desulfurization　ash,　rice　husk　ash　and　other　low-quality　solid　wastes　were　used　as　clinker-free　cementitious　materials　to　prepare　fluid　solidified　soil,　and　the　unconfined　compressive　strength,　drying　shrinkage　property,　heavy　metal　leaching　property　and　microstructure　of　fluid　solidified　soil　were　tested.　The　research　shows　that　the　flow　expansion　degree　and　unconfined　compressive　strength　of　fluid　solidified　soil　prepared　by　cementitious　materials　without　clinker　meet　the　requirements　of　general　filling　engineering,　the　drying　shrinkage　value　of　hardened　body　is　significantly　lower　than　that　of　cement　solidified　soil　with　the　same　content,　and　there　is　no　risk　of　excessive　leaching　toxicity　of　heavy　metals.　Under　the　synergistic　effect　of　various　solid　wastes,　the　soil　particles　aggregate　into　clusters,　and　the　pores　are　significantly　reduced.　The　flocculent　gel　and　acicular　ettringite　crystal　are　intertwined,　adhere　to　the　surface　of　soil　particles　and　connect　to　soil　particles,　which　enhance　the　strength　of　solidified　soil.　©　2022　Bulletin　of　the　Chinese　Ceramic　Society.　All　rights　reserved.